Apparatus for closing a carton



June 13, 1961 CHANDLER 2,987,973

APPARATUS FOR CLOSING A CARTON Filed March 24, 1959 3 Sheets-Sheet 1 -Inn. I Illllllll]llllllllllllIlllllllllllllllflll llll' INVENTOR. GROVER C. CHANDLER ATTORNEYS.

June 13, 1961 G. c. CHANDLER APPARATUS FOR CLOSING A CARTON 3 Sheets-Sheet 2 Filed March 24, 1959 r INVENTOR.

' GROVER C. CHANDLER ATTORNEYS.

June 13, 1961 G. c. CHANDLER 2,987,973

APPARATUS FOR CLOSING A CARTON Filed March 24, 1959 5 Sheets-Sheet 3 I 2 5 4 2 30 21 m "WI 1W 6 II/W i/f 33% 4 4 24 2 L A M g2 INVENTOR. GROVER C. CHANDLER BY w ATTORNEYS Jersey Filed Mar. 24, 1959, Ser. No. 801,587 4 Claims. (Cl. 93-52) This invention relates to a non-bulging end closure for a paperboard carton and to a preferred method and apparatus for providing such construction. Paperboard cartons of the type here concerned include opposed pairs of side walls which have end closure flaps hingedly connected to the end edges of at least one of such pair of side walls. To close the carton end, these flaps are folded over the open end of the carton in overlapping position, and there secured in place either by an adhesive or by the interlocking action of locking means provided on or in those flaps. These end closure flaps in the closed position commonly have a tendency to bulge outwardly away from the completely closed position, in which they would lie perpendicularly to the side walls. This tendency results from the fight inherent in the paperboard carton material; that is, from the tendency of the flaps to remain in or return to the original position in which they were co-planar with the carton side walls from which they extend and with which they are usually integral. This bulging of the end flaps results in an unsightly appearance, may interfere with subsequent handling of the closed carton, frequently leads to disengagement of the locked end closure flaps, and may permit escape of the contents of the carton through the gaps resulting from such bulging.

It is the principal object of this invention to provide a carton having an end closure of special configuration whereby this tendency of the closure flaps to bulge open is eliminated, and a method and means whereby a carton with such advantageous construction is provided. Details of this and other particular objects and advantages of the invention will become clear from the following description in connection with the appended drawings, in which:

FIGURE 1 is a perspective view of a carton incorporating this invention,

FIGURE 2 is a partial cross sectional view, taken along the line 2-2 of FIGURE 1, but showing a step in the closure of the carton end,

FIGURE 3 is a partial cross sectional view taken along the line 3-3 of FIGURE 1, showing the completely closed end of the carton,

FIGURE 4 is an enlarged view of a detail of that portion of the carton closure encircled in FIGURE 3,

FIGURE 5 is a perspective view of a preferred apparatus employed in the formation of the carton closure of this invention,

FIGURE 6 is a cross sectional view, partially cut away, taken along the line 6-6 of FIGURE 5,

FIGURE 7 is a cross sectional view, partially cut away, taken along the line 7-7 of FIGURE 5,

FIGURE 8 is a cross sectional view, partially cut away, taken along the line 8-8 of FIGURE 5,

FIGURE 9 is a cross sectional view, partially cut away, taken along the line 99 of FIGURE 5,

FIGURE 10 is a cross sectional view, partially cut away, taken along the line 1010 of FIGURE 5,

FIGURE 11 is a perspective view, partially cut away, taken from the left end of the apparatus shown in FIG- URE 5, and

FIGURE 12 is a perspective view of a somewhat modified carton incorporating the present invention.

FIGURE 1 shows a paperboard carton, which, aside from the incorporation of the present invention, is quite 2,987,973 Patented June 13, 1961 typical and is used for a multitude of packaging purposes, such as the packaging of food products. The carton 20 includes opposed pairs 21--22 and 23--24 of side walls (see also FIGURE 2), end closure flaps 25 and 26 hinged along score lines 29 to the edges of walls 21-22, and dust tabs 27 and 28 hinged to the end edges of walls 23 and 24. The carton preferably is made from a single piece of paperboard, the respective walls, flaps, and tabs being separated from each other by cut and score lines which usually are impressed into the paperboard carton material from the surface thereof which will form the exterior of the carton. The end of the carton opposite to that at which are provided flaps 25 to 28 may be closed by a similar series of flaps, or in any other conventional manner.

Referring also to FIGURE 5, in a preferred form of the carton a pair of male locking elements 30 are formed on flap 25, corresponding to and for interlocking engage ment with a pair of female locking elements 31 formed on flap 26. The carton as thus far described is conventional and accordingly is not described in greater detail.

Referring particularly to FIGURE 2, the end of the carton is closed by consecutively enfolding flaps 26 and 25, locking elements 30 and 31 being conventionally interlocked to restrain the flaps in enfolded position where they overlie and close the end of the carton. However, the fight or memory of the paperboard carton material gives rise to a tendency of flaps 25 and 26 to return to their original position shown at the right-hand end of FIGURE 5, in which they were co-planar with Walls 21 and 22 to which they are respectively hinged. This gives rise to an unsightly bulging of the end of the carton as clearly disclosed in FIGURE 2 and a consequent departure from the rectangular parallelepiped form which is desired. Aside from mere unsightliness this bulging may interfere with subsequent wrapping or other handling operations, may lead to disengagement of the locks, and the gap formed in the carton end may permit leakage of the contents of the carton. Accordingly, it is de sired, but until this invention there had not been attained, a convenient and economical carton construction which would eliminate this difficulty.

The carton shown in FIGURE 1, and shown in greater detail in FIGURES 3 and 4 incorporates constructional features which eliminate the tendency of the carton end closure to bulge. Specifically, this invention calls for incorporating in each of flaps '25 and 26 immediately adjacent hinge score lines 29 a further score line 35, score lines 35 being formed after flaps 25 and 26 are enfolded over the end of the carton. The incorporation of these additional score lines 35 provides a further bending and breakage of the paperboard carton material immediately adjacent the conjunction of flaps 25 and 26 with their respective side walls 21 and 22, thus essentially eliminating the fight or memory of the paperboard along these areas, and permitting flaps 25 and 26 to lie flatly over the end of the carton in interlocked engagement with each other.

Although the incorporation of additional score or impression lines 35 is particularly advantageous in connection with lock end cartons as depicted, where there is inherently a tendency toward some looseness or play in the locking action, the construction may also be usefully employed in cases where the opposed end flaps are to be adhered in overlapping relation by a suitable adhesive, tabs or the like, or where they are to be stapled or other wise fastened together.

For enfoldi-ng and locking its end, the carton enters the apparatus at the right end as seen in FIGURE 5, and progresses leftwardly while the closing operation is performed. In the first step, dust tabs 27 and 28 are folded inwardly, in which position they are retained by tongue- 3 40 as the carton progresses through the apparatus. The remainder of the enfolding and locking operation is performed by particularly conformed elements or portions of upper and lower plows 41 land 42.

As the carton progresses from the right hand position in FIGURE .5 to the nextstep, a cross section of which is shown in FIGURE 6, the side walls of the carton are supported by plow extensions 43 and-44, and a specifically conformed plow element 45 initiates the enfolding of flap 26.

Further progression of the carton to the next step, a cross section of which is shown in FIGURE 7, brings flap 26 into .enfolding relation with plow element 46, by which flap .25 has also been contacted for the initiation of enfolding. As will be clear from study ofthe stations at .cross sections 6-6 and 77 of FIGURE 5, fiap 26is enfolded ahead of flap 25, so that flap 2'5 overlies flap '26. As particularly shown in FIGURE 7, the action of plow element 46 breaks open locking elements .31 for the entry thereinto of locking elements .30.

.As the carton proceeds toward the nextstep, a cross section of which is shown in FIGURE 8, element 46 progressively brings flap 25 into a planar condition perpendicular to wall 21, while oppositely disposed plow element 47 acts similarly upon flap 26. The carton and apparatus are of course so proportioned that as flaps 25 and 26 reach the position Where they are flatly folded over the end of the carton perpendicularly to the side walls '21 and 22, locking elements 30 and 31 are fully engaged. Obviously, the opposite end of the carton is supported to insure firm contact of the carton with plows 41 and 42, but since such supporting means is completely conventional, it is not further detailed.

Still referring to FIGURE 5, the carton then progresses past a forming block 50, details of which are shown in FIGURE 9, which firmly presses the flaps 25 and 26 into the ultimate closed position. As seen, portions 51 of block .50 are cut away to reduce the frictional contact between the block and the carton.

The carton then passes into contact with a rotatable roller 55, shown in cross section in FIGURE 10, which performs the final operation by which the ultimate in appearance and operation of this carton closure is insured. Roller 55, mounted to revolve about its axis 56, is provided with a series of'annular grooves and lands. Included is a pair of grooves 57 of diameter to quite precisely accommodate the final height of side walls 21 and 22, and a pair of .sharp edged lands 58 adapted to provide :a sharp score 35 in fiaps 25 and 26'immediately adjacent their hinge score connections 29 to side Walls 21 and 22. As is clear from FIGURE 10, the diameter of lands 58 is sufiiciently great to cause a positive deformation of the carton materialas the lands impress the sharp score in the surface of flaps 25 and 26. Also included is a central land 59 of diameter substantially equal to that of lands 58, which serves to support the central portion of flaps 25 and 26 during the scoring operation now being described. A pair of outwardly positioned lands 60pmvides support for side walls 21 and 22 immediately adjacent hinge connections 29 during the current scoring operation. It will be seen that the surface of land 6% lying toward lands 58 is beveled as at 61 to facilitate and guide the impressrnent of the carton material between lands 58 and 60 and into grooves 57. This impressment of the carton material into grooves 57, and the positive sharp scoring action of lands 58 provides a definite and sharp break and deformation of the carton material, thus substantially eliminating the fight or memory of the car ton material, with the result that a cartonclosure of stable dimension and configuration is achieved. All bulging of the carton closure is eliminated, thus avoiding the unsightliness, hazard to further manipulation and dangers of leakage, which are inherent in carton closures resulting from convention operations.

FIGURE 12 illustrates a slightly modified form of carton 20a incorporating the present invention, comprising side walls 21a and 23a, and locking end closure flaps 25a and 26a connected to the side walls :along score lines 2%. Flap 26a includes a female locking element 31a coasting with a corresponding male locking element (not shown) on flap 25a, this locking construction being conventional and substantially as depicted in United States Patent No. 2,798,656.

As in the previous embodiment sharp score lines 35a are impressed into flaps 25a and 26a immediately adjacent hinge connections 29a, to provide a completely fiat and stable carton end closure.

Having now described a preferred embodiment of the invention, various modifications and alternatives, not .involving departure from the present invention, will be apparent to those skilled in the art. Accordingly it is intended that the invention be limited as specifically set forth in the appended claims.

Iclairn:

1. Apparatus for providing the non-bulging closure of the end of a paperboard carton having opposed pairs of side walls and an opposed pair of end closure flaps hingedly connected to-the end edges of one opposed pair of said walls, the apparatus including folding plows to enfold the flaps over theopen end of the carton into overlying position with respect to each other to close such open end and rotatable scoring means adapted to impresss a score line into the fiaps immediately adjacent their'hinge connections 'to said walls, said means comprising a roller having sharp edged firstannular portions adapted to contact said fiaps immediately adjacent their hinge connections to the side walls to impress a score line into said flaps along such line of contact, and second annular portions spaced outwardly from said second portions and adapted tosupport said one opposed pair of side walls while the carton is engaged by said roller, said first annular portions being spaced inwardly from the second annularportions .to permit impressment there'between of a portion of the carton material at the hinge connection of said flaps to said side walls.

2. Apparatus according to claim 1, further characterized by the fact that the second annular portions are beveled toward the first annular portions to guide said portion of the carton material for impressment between said annular portions. 7

3. Apparatus according to claim l, in which said roller further includes a central annular portion adapted to contact the flaps intermediate said hinge connections after the flaps have been enfolded by said plows,,to restrain said flapsintheir completely enfolded position substantially perpendicular to the side walls. I 4. Apparatus according to claim 3, further characterized by the fact that the second annular portions are beveled .toward the first annular portions to-guide said portion of the carton material for impressment between said annular'portions.

' References Cited in theme of this patent UNITED STATES PATENTS 

